Field of Invention
[0001] This application belongs to the technical fields of materials chemistry and catalytic
chemistry, in particular it relates to a method for the synthesis of a type of FER/MOR
composite molecular sieve.
Background Technology
[0002] FER molecular sieve is a type of laminar molecular sieve material that has a Ferrierite
zeolite topographical structure (
US 4016245), which belongs to the orthorhombic crystals family and which possesses a perpendicularly
intersecting two-dimensional channels system, having ten-membered channels being roughly
0.42 × 0.54nm in size and eight-membered channels roughly 0.35 × 0.48nm in size. Due
to the suitability of the channels and its excellent thermal stability and acidity,
it has been widely adopted in isomerization, polymerization, cracking and other such
hydrocarbon conversion reaction processes. Traditional organic templates used in the
synthesis of FER molecular sieves are mainly: ethylenediamine or pyrrolidine, butanediamine,
1,4-dimethyl-piperazine, hexamethyleneimine and cyclohexane.
[0003] MOR molecular sieve is a molecular sieve that has a Mordenite zeolite topographical
structure, which has twelve-membered ring (around 0.67 × 0.70 nm) main channels which
follow the C axis and parallel eight-membered ring (around 0.28 × 0.57 nm) side channels.
Its excellent thermal stability and adjustable acidity has resulted in its wide adoption
in the petrochemicals and fine chemicals fields.
[0004] The term composite molecular sieve refers to a co-crystallization product formed
from two or more molecular sieves, being a composite crystal with the structural characteristics
of two or more molecular sieves; this type of molecular sieve will generally exhibit
characteristics that are different to those of single molecular sieves or the corresponding
mechanically mixed materials. Due to composite molecular sieves having multiple structures
and superimposed functions, the drawbacks of a single type of channel are overcome,
making them advantageous in terms of molecular adsorption and diffusion and resulting
in their having widespread potential applications in the refining catalysts field.
Composite molecular sieves that have already been reported are MFI/MEL, BEA/MOR, FAU/EMT,
STF/SFF and OFF/ERI. The scientific article
JONGKIND H. ET AL: "Synthesis and characterisation of zeolites using saturated cyclic
amines as structure-directing agents", MICROPOROUS MATERIALS, vol. 10, no. 4-6, 1
July 1997, pages 149-161 teaches a method to prepare a FER/MOR composite molecular sieve from a synthesis
mixture comprising an organic structure directing agent (piperidine).
[0005] But in industrial manufacturing of traditional molecular sieves it is necessary to
use an organic template. The use of an organic template not only increases production
costs, but also results in environmental pollution.
[0006] Apart from this, the activity of composite molecular sieve catalysts is closely connected
with the ratio of the two phases, whilst different catalytic reactions have different
optimum ratios of the two phases.
[0007] Due to this, there is an urgent need to develop a green method allowing synthesis
of composite molecular sieves of which the ratio of the crystal phase can be controlled
and do not require the use of an organic template.
Invention Simplified Description
[0008] This application consists of a type of FER/MOR composite molecular sieve, the synthesis
of the FER/MOR composite molecular sieve being controlled by adjustment of the ratio
of the seed crystal phases and the acidity/alkalinity of the synthesis system, yielding
a dual-phase FER/MOR composite crystalline molecular sieve the ratio of the crystalline
phases of which can be controlled, which doesn't require the addition of any organic
template. The technical operations required by this method are simple, are environmentally
friendly, are low in cost and result in a product with excellent crystalline properties,
which has excellent potential in terms of its applications. Also disclosed herein
but not forming part of the present invention is the FER/MOR composite molecular sieve
synthesised using this method.
[0009] One aspect of this invention, is that this invention consists of a method for the
synthesis of a type of FER/MOR composite molecular sieve, that method including the
following steps: mixing of FER seed crystals, MOR seed crystals, a silicon source,
an aluminium source, water and an acid or alkali, thus yielding a reaction mixture,
wherein the pH of the reaction mixture is 9 or above; causing that reaction mixture
to undergo a crystallization reaction, in order to obtain the FER/MOR composite molecular
sieve, whereby the aforementioned crystallization reaction takes place under conditions
whereby there is no organic template.
[0010] According to certain embodiments of this application, the aforementioned silicon
source is solid silica gel, colloidal silica, sodium silicate, silicon dioxide, tetraethoxysilane,
silicic acid or any mixture of these.
[0011] According to certain embodiments of this application, the aforementioned silicon
source is SiO
2.
[0012] According to certain embodiments of this application, the aforementioned aluminium
source is sodium metaaluminate, aluminium hydroxide, aluminium sulphate, boehmite
or any mixture of these.
[0013] According to certain embodiments of this application, the aforementioned aluminium
source is Al
2O
3.
[0014] According to certain embodiments of this application, the proportion of the total
mass of FER seed crystals and MOR seed crystals accounted for by the FER seed crystals
mass is 5-95%.
[0015] According to certain embodiments of this application, the proportion of the total
mass of FER seed crystals and MOR seed crystals accounted for by the MOR seed crystals
mass is 5-95%.
[0016] According to certain embodiments of this application, the proportion of the total
mass of FER seed crystals and MOR seed crystals accounted for by the FER crystals
mass is not less than 33%, 50%, 67%, 71% or 75%.
[0017] According to certain embodiments of this application, the aforementioned alkali is
an inorganic alkali.
[0018] According to certain embodiments of this application, the aforementioned inorganic
alkali is either sodium hydroxide, potassium hydroxide, ammonium hydroxide or any
mixture of these.
[0019] According to certain embodiments of this application, the aforementioned acid is
an inorganic acid.
[0020] According to certain embodiments of this application, the aforementioned inorganic
acid is either sulphuric acid, hydrochloric acid, nitric acid or any mixture of these.
[0021] In accordance with the present invention, the pH of the reaction mixture is 9 or
above.
[0022] According to certain embodiments of this application, the ratio between the OH- and
the mol number of atomic aluminium within the reaction mixture is between 1.25: 1
and 15:1.
[0023] According to certain embodiments of this application, the mass of FER seed crystals
or MOR seed crystals is between 0.1-15.0% of total of the converted mass of atomic
silicon or the converted mass of atomic aluminium within the aforementioned reaction
mixture.
[0024] According to certain embodiments of this application, the ratio between the mol number
of atomic silicon and the mol number of atomic aluminium within the reaction mixture
is between 2.5:1 and 25:1.
[0025] According to certain embodiments of this application, the ratio between the water
and the atomic aluminium mol number within the reaction mixture is between 100:1 and
1000:1.
[0026] According to certain embodiments of this application, the aforementioned crystallization
reaction includes subjecting the reaction mixture to a reaction under conditions of
self-generated pressure and a temperature of between 413.15 to 493.15 K (140-220°C)
for between 20-120 hours.
[0027] According to certain embodiments of this application, the aforementioned crystallization
reaction takes place in a reactor which includes a rotating oven, the rate of rotation
of the rotating oven being between 30-100 rpm.
[0028] According to certain embodiments of this application, prior to commencing the Crystallization
reaction, pre-crystallization of the reaction mixture takes place under conditions
of 353.15 to 393.15 K (80-120°C) for between 4-24 hours.
[0029] According to certain embodiments of this application, the aforementioned pre-crystallization
takes place in a reactor with a rotating oven, the speed of rotation of that rotating
oven being between 30-100 rpm.
[0030] According to certain embodiments of this application, after the aforementioned crystallization
reaction has taken place, this also includes separation of the resultant FER/MOR composite
molecular sieve.
[0031] According to certain embodiments of this application, the aforementioned FER seed
crystals and MOR seed crystals are processed by calcination prior to the mixing step.
[0032] According to certain embodiments of this application, the aforementioned FER seed
crystals or MOR seed crystals are ammonium type molecular sieve, hydrogen type molecular
sieve or sodium type molecular sieve.
[0033] Disclosed herein but not forming part of the present invention is an FER/MOR composite
molecular sieve synthesised according to the method outlined in this application.
[0034] The FER crystal phase mass percentage of FER/MOR composite molecular sieve is 8%.
[0035] The FER crystal phase mass percentage of the FER/MOR composite molecular sieve is
at least 13%, or at least 20%, or at least 40%, or at least 45%, or at least 65%,
or at least 75%, or at least 83%.
[0036] Also disclosed herein but not forming part of the present invention is a use for
the FER/MOR composite molecular sieve synthesised according to the method outlined
in this application in the skeletal isomerization of butene.
Appended Diagram Simplified Description
[0037]
Fig. la is the UV-Raman spectrum of FER single-phase crystalline molecular sieve,
MOR single-phase crystalline molecular sieve, FER/MOR composite molecular sieve, mechanically
mixed FER single-phase crystalline molecular sieve and MOR single-phase crystalline
molecular sieve;
Fig. 1b is the hyperpolarized 129Xe NMR spectrum of FER single-phase crystalline molecular sieve, MOR single-phase
crystalline molecular sieve, FER/MOR composite molecular sieve, mechanically mixed
FER single-phase crystalline molecular sieve and MOR single-phase crystalline molecular
sieve;
Fig. 2 is the X-ray diffraction (XRD) spectrum of the FER/MOR composite molecular
sieve obtained according to examples 1, 2 and 3;
Fig. 3 is a scanning electron microscope (SEM) image of the FER/MOR composite molecular
sieve obtained according to claim 1.
Invention Detailed Description
[0038] This application provides a method for the synthesis of a type of FER/MOR composite
molecular sieve.
[0039] The method for the synthesis of a type of FER/MOR composite molecular sieve provided
by this application includes the following steps: mixing FER seed crystals, MOR seed
crystals, a silicon source, an aluminium source, water and an acid or alkali, thus
yielding a reaction mixture, wherein the pH of the reaction mixture is 9 or above;
that reaction mixture is then subjected to a crystallization reaction, yielding the
FER/MOR composite molecular sieve, whereby that crystallization reaction takes place
under circumstances where there is no organic template.
[0040] In this application, the term "FER seed crystals" refers to a single-phase crystalline
material consisting of naturally or artificially synthesised Ferrierite zeolite. The
main elements within the FER seed crystals are silicon, aluminium, coordinated oxygen
atoms and inorganic cations, its basic structural units being three dimensional crystalline
material with a skeletal structure formed from silicon-oxygen tetrahedrons or aluminium-oxygen
tetrahedrons. The FER seed crystals have a ten-membered ring and eight-membered ring
channel system. The FER seed crystals can be natural Ferrierite; alternatively they
can be artificially synthesised FER molecular sieve, such as ZSM-35 molecular sieve,
Sr-D Brewsterite zeolite, Na type Ferrierite zeolite or Ca-Na type Ferrierite zeolite.
In certain embodiments of this application, the FER seed crystals are ZSM-35 molecular
sieve.
[0041] The term "MOR seed crystals" used in this application refers to a single phase crystalline
material consisting of either natural or artificial Mordenite zeolite. The main elements
within the MOR seed crystals are silicon, aluminium, coordinated oxygen atoms and
inorganic cations, its basic structural units being three dimensional crystalline
material with a skeletal structure formed from silicon-oxygen tetrahedrons or aluminium-oxygen
tetrahedrons. The MOR seed crystals have a twelve-membered ring and eight-membered
ring channel system. The MOR seed crystals may be natural Mordenite zeolite; alternatively
they may be artificially synthesised Mordenite zeolite molecular sieve. In certain
embodiments of this application, the MOR seed crystals are natural Mordenite zeolite.
[0042] The term "silicon source" used in this application refers to a material containing
silicon, which may be either pure silicon or a compound or mixture formed of a composite
of silicon and other materials. In certain embodiments of this application, the aforementioned
silicon source provides the silicon-oxygen tetrahedral structural units within the
FER/MOR composite molecular sieve. In certain embodiments of this invention, the aforementioned
silicon source is an oxide of silicon. In certain embodiments of this application,
the aforementioned silicon source is SiO
2. In certain applications of this application, the aforementioned silicon source is
solid silica gel, colloidal silica, sodium silicate, silicon dioxide, tetraethoxysilane,
silicic acid or any mixture of these.
[0043] The term "aluminium source" used in this application refers to a material that contains
aluminium, which may be pure aluminium or a compound or mixture formed of a composite
of aluminium and other materials. In certain embodiments of this application, the
aforementioned aluminium source provides the aluminium-oxygen tetrahedral structural
units within the FER/MOR composite molecular sieve. In certain embodiments of this
application, the aforementioned aluminium source is an oxide of aluminium. In certain
embodiments of this application, the aforementioned aluminium source is Al
2O
3. In certain embodiments of this application, the aforementioned aluminium source
is sodium metaaluminate, aluminium hydroxide, aluminium sulphate, boehmite (SB powder)
or any mixture of these.
[0044] The term "FER/MOR composite molecular sieve" used in this application refers to a
composite crystal which possesses the structural characteristics of FER and MOR molecular
sieves, whereby the structure of that composite crystal contains both FER ten-membered
ring channels and eight-membered ring channels and MOR twelve-membered ring channels
and eight-membered ring channels, whereby that type of molecular sieve is not a simple
mixed material consisting of mechanically mixed FER single-phase crystalline molecular
sieve and MOR single-phase crystalline molecular sieve. FER/MOR composite molecular
sieve possesses multiple structures and superimposed functions, providing many advantages
in terms of molecular adsorption and diffusion. The FER/MOR composite molecular sieve
may be eutectic.
[0045] In traditional molecular sieve synthesis methods an organic template is used. The
organic template refers to a compound that generally acts as a structural guide during
molecular sieve synthesis. Traditional organic templates mainly include ethylenediamine,
pyrrolidine, butanediamine, 1,4-dimethyl-piperazine, hexamethyleneimine and cyclohexane.
The use of an organic template results in increased costs, whilst after the molecular
sieve has been generated, the molecular sieve must be subjected to calcining to eliminate
the organic template from within it; during the calcining process, it is possible
that the organic template does not undergo complete pyrolysis with the result that
there are blocked channels within the zeolite, which then affects its performance.
In this application consisting of a method for the synthesis of a type of FER/MOR
composite molecular sieve, there is no organic template used. As a result of this,
the manufacturing costs associated with the method for synthesis of FER/MOR composite
molecular sieve to which this application relates are reduced, whilst the catalytic
performance of the FER/MOR composite molecular sieve is increased.
[0046] The inventors where this application is concerned also discovered that by adjusting
the proportions of FER and MOR seed crystals added to the initial reaction, it is
possible to obtain a series of FER/MOR composite molecular sieves with different relative
FER content. By adjusting the ratio of FER and MOR seed crystals added in the initial
reaction, it is possible to obtain a dual-phase FER/MOR composite molecular sieve
with adjustable crystalline phase proportions. The inventors where this application
is concerned discovered that when the ratio between the mass of FER seed crystal added
to the initial reaction and total mass of total FER seed crystals and MOR seed crystals
was increased, the mass percentage of the FER crystal phase within the composite molecular
sieve also increased; as the ratio between the mass of FER seed crystal added to the
initial reaction and total mass of total FER seed crystals and MOR seed crystals was
reduced, the mass percentage of the FER crystal phase within the composite molecular
sieve was also reduced. In certain embodiments of this application, the ratio of the
mass of the FER seed crystals added in the initial reaction to the total mass of the
aforementioned FER seed crystals and MOR seed crystals is respectively 5-95%, or 5-90%,
or 5-80%, or 5-70%, or 5-60%, or 5-50%, or 5-40%, or 5-30%, or 5-20%, or 5-10%, or
10-95%, or 20-95%, or 30-95%, or 40-95%, or 50-95%, or 60-95%, or 70-95%, or 80-95%,
or 90-95%. According to certain embodiments of this application, the ratio of the
mass of the MOR seed crystals added in the initial reaction to the total mass of the
aforementioned FER seed crystals and MOR seed crystals is respectively 5-95%, or 5-90%,
or 5-80%, or 5-70%, or 5-60%, or 5-50%, or 5-40%, or 5-30%, or 5-20%, or 5-10%, or
10-95%, or 20-95%, or 30-95%, or 40-95%, or 50-95%, or 60-95%, or 70-95%, or 80-95%,
or 90-95%.
[0047] In certain embodiments, the ratio of the mass of the FER seed crystals added in the
initial reaction to the total mass of the aforementioned FER seed crystals and MOR
seed crystals is respectively not less than 5%, or 10%, or 20%, or 30%, or 40%, or
50%, or 60%, or 70%, or 80%, or 90%. In certain embodiments, the ratio of the mass
of the FER seed crystals added in the initial reaction to the total mass of the aforementioned
FER seed crystals and MOR seed crystals is respectively not more than 95%, or 90%,
or 80%, or 70%, or 60%, or 50%, or 40%, or 30% or 20% or 10%. In certain embodiments
of this application the ratio of the mass of the FER seed crystals added in the initial
reaction to the total mass of the aforementioned FER seed crystals and MOR seed crystals
is respectively not less than 33%, 50%, 67%, 71% or 75%.
[0048] The inventors where this application is concerned discovered that by adjusting the
acidity/alkalinity of the system, it was possible to obtain a dual-phase FER/MOR composite
molecular sieve the ratio of the crystalline phases of which could be controlled.
According to certain embodiments of this application, the aforementioned alkali is
an inorganic alkali. According to certain embodiments of this application, the aforementioned
inorganic alkali is either sodium hydroxide, potassium hydroxide, ammonium hydroxide
or any mixture of these.
[0049] According to certain embodiments of this application, the aforementioned acid is
an inorganic acid. According to certain embodiments of this application, the aforementioned
inorganic acid is either sulphuric acid, hydrochloric acid, nitric acid or any mixture
of these.
[0050] In accordance with the present invention, the pH of the reaction mixture is 9 or
above. According to certain embodiments of this application, the pH of the aforementioned
reaction mixture is between 9-14, or 10-14, or 11-14, or 12-14, or 13-14, or 9-10,
or 9-11, or 9-12, or 9-13.
[0051] The inventors where this application is concerned discovered that by adjusting the
alkalinity of the system, as the ratio between the OH and the mol number of atomic
aluminium within the reaction mixture increased, the mass percentage of the MOR crystal
phase within the composite molecular sieve also increased; as the ratio between the
OHand the mol number of atomic aluminium within the reaction mixture decreased, the
mass percentage of the MOR crystal phase within the composite molecular sieve also
decreased. According to certain embodiments of this application, the ratio between
the OH- and the mol number of atomic aluminium within the reaction mixture is between
1.25:1 and 15:1, or 1.25:1 and 10:1, or 1.25:1 and 5.1, or 1.25:1 and 2.5: 1, or 2.5:
1 and 15:1, or 5: 1 and 15:1, or 10:1 and 15:1. In certain embodiments, the ratio
between the OH and the mol number of atomic aluminium within the reaction mixture
is not less than 1.25: 1, or 2.5: 1. In certain embodiments, the ratio between the
OH and the mol number of atomic aluminium within the reaction mixture is not more
than 15:1, or 10:1, or 5:1, or 2.5: 1. In certain embodiments of this application,
the ratio between the OH- and the mol number of atomic aluminium within the reaction
mixture is 1.8, 2.8, 3.0, 3.1, 3.5 or 4.5. In this application, the mol number of
OH refers to hydroxyl radicles (OH") within the solution, the source of the OH- being
the alkali and the product of the reaction, for instance NaAlO
2 or Na
2O undergoing a reaction generating OH
-.
[0052] According to certain embodiments of this application, the mass of FER seed crystals
or MOR seed crystals is 0.1-15.0%, or 0.1-10.0%, or 0.1-5%, or 0.5-15.0%, or 1.0-15.0%,
or 5.0-15.0%, or 10.0-15.0% of the total of the converted mass of atomic silicon and
the converted mass of atomic aluminium within the aforementioned reaction mixture.
In certain embodiments, the mass of FER seed crystals or MOR seed crystals is at least
0.1%, or 0.5%, or 1.0%, or 2.0%, or 5.0% of the total of the converted mass of atomic
silicon and the converted mass of atomic aluminium within the aforementioned reaction
mixture. In certain embodiments, the mass of FER seed crystals or MOR seed crystals
is at most 15%, or 10% or 5% of the total of the converted mass of atomic silicon
and the converted mass of atomic aluminium within the aforementioned reaction mixture.
In certain embodiments of this application, the mass of FER seed crystals is 1.0%,
2.0%, 2.5%, 3.0%, 5.0%, 8.0% or 10% of the total of the converted mass of atomic silicon
within the aforementioned reaction mixture and the converted mass of atomic aluminium
within the aforementioned reaction mixture. In certain embodiments of this application,
the mass of MOR seed crystals is 0.7%, 1.0%, 2.0%, 4.0%, 5.0%, or 10% of the total
of the converted mass of atomic silicon within the aforementioned reaction mixture
and the converted mass of atomic aluminium within the aforementioned reaction mixture.
[0053] In this application, the mol number of atomic silicon within the reaction mixture
refers to the mol number of silicon atoms within the reaction mixture. In this application,
the mol number of atomic aluminium within the reaction mixture refers to the mol number
of aluminium atoms within the reaction mixture.
[0054] The formula for calculating the atomic silicon mol number within the reaction mixture
is as follows:
atomic silicon mol number within the reaction mixture = mass of the material containing
silicon/the molecular mass of the material containing silicon x the number of atoms
of silicon within the chemical formula of the material containing silicon.
[0055] The formula for calculating the atomic aluminium mol number within the reaction mixture
is as follows:
atomic aluminium mol number within the reaction mixture = mass of the material containing
aluminium/the molecular mass of the material containing aluminium x the number of
atoms of aluminium within the chemical formula of the material containing aluminium.
[0056] In this application, converted mass of atomic silicon within the reaction mixture
refers to the mol number of atomic silicon within the reaction mixture corresponding
to the mol number of the converted mass of SiO
2. In this application, converted mass of atomic aluminium within the reaction mixture
refers to the mol number of atomic aluminium within the reaction mixture corresponding
to the mol number of the converted mass of Al
2O
3. The formula for calculating the converted mass of atomic silicon within the reaction
mixture, being the mass of SiO
2 calculated based on the mol number of atomic silicon within the reaction mixture,
is as follows:
converted mass of atomic silicon within the reaction mixture = mol number of atomic
silicon within the reaction mixture x the molecular weight of SiO
2.
[0057] For instance, if there was 1 mol of atomic silicon within the reaction mixture, this
corresponds to 1 mol of SiO
2, as a result of this the mass of SiO
2 after conversion is 1 × 60 = 60g, therefore the converted mass of 1 mol of atomic
silicon would be 60g.
[0058] The converted mass of atomic aluminium within the reaction mixture, being the mass
of Al
2O
3 calculated based on the mol number of atomic silicon within the reaction mixture,
is as follows:
converted mass of atomic aluminium within the reaction mixture = ½ x mol number of
atomic silicon x the molecular weight of Al
2O
3.
[0059] For instance, if there was 1 mol of atomic aluminium within the reaction mixture,
corresponding to 0.5mol Al
2O
3, the mass of Al
2O
3 calculated would be 0.5 × 102 =51g, therefore the converted mass of 1 mol of atomic
aluminium is 51g.
[0060] In certain embodiments, by adjusting the proportion of atomic silicon and atomic
aluminium, it is possible to obtain a dual-phase FER/MOR composite molecular sieve.
According to certain embodiments of this application, the ratios of atomic silicon
mol number to atomic aluminium mol number within the aforementioned reaction mixture
are 2.5:1-25:1, or 2.5:1-20:1, or 2.5:1 -15:1, or 2.5:1-10:1, or 2.5:1-5:1, or 5:1-25:1,
or 10:1-25:1, or 15:1-25:1, or 20:1-25.1. In certain embodiments, the ratio of the
atomic silicon mol number to atomic aluminium mol number is not less than 2.5:1, or
5:1, or 10:1, or 15:1. In certain embodiments, the ratio of the atomic silicon mol
number to atomic aluminium mol number is not more than 25:1, or 20:1 or 150:1. In
certain embodiments of this application, the ratio of the atomic silicon mol number
to atomic aluminium mol number is 9:1, 10:1, 11:1, 11.5:1, 16.5:1 or 19.5:1.
[0061] In certain embodiments, the ratio of water and atomic aluminium mol number within
the aforementioned reaction mixture is 100:1-1000:1, or 1000:1-750:1, or 100:1-500:1,
or 100:1-250:1, or 250:1-1000:1, or 500:1-1000:1, or 750:1-1000:1. In certain embodiments,
the ratio of water and atomic aluminium mol number is not less than 100:1, or 250:
1, or 500:1. In certain embodiments, the ratio of water and atomic aluminium mol number
is not more than 1000:1, or 750: 1 or 500: 1. In certain embodiments of this application,
the ratio of water and atomic aluminium mol number is 309: 1, 331: 1, 387:1, 646:
1, 650: 1, 780: 1 or 963:1.
[0062] According to the method of this application, the aforementioned FER seed crystals,
MOR seed crystals, silicon source, aluminium source, water and acid or alkali may
be mixed in any order using any method, to obtain the aforementioned reaction mixture.
In certain embodiments of this application, ultra-sound dispersion and/or mixing are
used to bring about the even mixing of the reaction mixture.
[0063] In certain embodiments of this application, the reaction mixture obtained is sealed
in a reactor vessel to carry out the crystallization reaction.
[0064] In certain embodiments of this application, the aforementioned crystallization reaction
includes subjecting the reaction mixture to a reaction under conditions of self-generated
pressure and a temperature of between 413.15 to 493.15 K (140-220°C) for between 20-120
hours. In certain embodiments, the temperature of the crystallization reaction is
413.15 to 473.15 K (140-200°C), or 413.15 to 453.15 K (140- 180°C), or 413.15 to 433.15
K (140-160°C), or 433.15 to 493.15 K (160-220°C), or 453.15 to 493.15 K (180-220°C),
or 473.15 to 493.15 K (200-220°C). In certain embodiments, the temperature of the
crystallization reaction is not less than 413.15 K (140°C), or 433.15 K (160°C), or
453.15 K (180°C). In certain embodiments, the temperature of the crystallization reaction
does not exceed 493.15 K (220°C), or 473.15 K (200°C), or 453.15 K (180°C).
[0065] In certain embodiments, the crystallization reaction time is 20-120 hours, or 20-100
hours, or 20-80 hours, or 20-60 hours, or 20-40 hours, or 40-120 hours, or 60-120
hours, or 80-120 hours, or 100-120 hours. In certain embodiments, the crystallization
reaction time is not less than 20 hours, or 40 hours, or 60 hours. In certain embodiments,
the crystallization reaction time is not more than 120 hours, or 100 hours, or 80
hours, or 60 hours.
[0066] Based on certain embodiments of this application, the aforementioned crystallization
reaction takes place under hydrothermal conditions, within a sealed container, a liquid
acting as the medium, preparation of the crystals occurring at a certain temperature
and self-generated pressure. In certain embodiments, the hydrothermal temperature
is 413.15 to 493.15 K (140- 200°C), or 413.15 to 473.15 K (140-200°C), or 413.15 to
453.15 K (140-180°C), or 413.15 to 433.15 K (140-160°C), or 433.15 to 493.15 K (160-220°C),
or 453.15 to 493.15 K (180-220°C), or 473.15 to 493.15 K (200- 220°C). In certain
embodiments, the hydrothermal temperature is not less than 413.15 K (140°C), or 433.15
K (160°C), or 453.15 K (180°C). In certain embodiments, the hydrothermal temperature
is not greater than 493.15 K (220°C), or 473.15 K (200°C), or 453.15 K (180°C).
[0067] According to certain embodiments of this application, the aforementioned crystallization
reaction takes placed within a reactor that includes a rotating oven, the rate of
rotation of that rotating oven being 30-100 rpm. In certain embodiments, the rate
of rotation of the reactor is not less than 30 rpm, or 40 rpm, or 50 rpm, or 60 rpm,
or 70 rpm, or 80 rpm, or 90 rpm. In certain embodiments, the rate of rotation of the
reactor is not greater than 100 rpm, or 90 rpm, or 80 rpm, or 70 rpm, or 60 rpm, or
50 rpm, or 40 rpm. In certain embodiments of this application, the reactor is a reaction
vessel or synthesis vessel, or a reactor vessel or synthesis vessel with a rotating
oven.
[0068] In certain embodiments of this application, before the crystallization reaction takes
place, the reaction mixture is subjected to pre-crystallization for 5-24 hours at
353.15 to 393.15 K (80-120°C). Pre-crystallization generally refers to slow formation
of crystals, a process that provides a nucleus for the crystals. In certain embodiments,
the pre-crystallization temperature is 353.15 to 393.15 K (80-120°C), or 353.15 to
383.15 K (80-110°C), or 353.15 to 373.15 K (80-100°C), or 353.15 to 363.15 K (80-90°C),
or 363.15 to 393.15 K (90-120°C), or 373.15 to 393.15 K (100-120°C), or 383.15 to
393.15 K (110-120°C).
In certain embodiments, the pre-crystallization temperature is not less than 353.15
K (80°C), or 363.15 K (90°C), or 373.15 K (l 00°C). In certain embodiments, the pre-crystallization
temperature is not greater than 393.15 K (120°C), or 383.15 K (110°C), or 373.15 K
(100°C).
[0069] In certain embodiments, the pre-crystallization time is 4-24 hours, or 8-24 hours,
or 10-24 hours, or 12-24 hours, or 14-24 hours, or 16-24 hours, or 18-24 hours, or
20-24 hours, or 22-24 hours, or 4-22 hours, or 4-20 hours, or 4-18 hours, or 4-16
hours, or 4-14 hours, or 4-12 hours, or 4-10 hours, or 4-8 hours. In certain embodiments
the pre-crystallization time is no less than 4 hours, or 8 hours, or 10 hours, or
12 hours, or 14 hours, or 16 hours, or 18 hours, or 20 hours, or 22 hours. In certain
embodiments, the pre-crystallization time is not greater than 24 hours, not greater
than 22 hours, not greater than 20 hours, not greater than 18 hours, not greater than
16 hours, not greater than 14 hours, or 12 hours, or 10 hours, or 8 hours.
[0070] According to certain embodiments of this application, the aforementioned pre-crystallization
takes place in a reactor which includes a rotating oven, the rate of rotation of the
aforementioned oven being 30-100 rpm. In certain embodiments, the rate of rotation
of the aforementioned oven is not less than 30 rpm, or 40 rpm, or 50 rpm, or 60 rpm,
or 70 rpm, or 80 rpm, or 90 rpm. In certain embodiments, the rate of rotation of the
aforementioned oven is not higher than 100 rpm, or 90 rpm, or 80 rpm, or 70 rpm, or
60 rpm, or 50 rpm, or 40 rpm.
[0071] In certain embodiments of this application, after the crystallization reaction has
taken place, this includes a further step of separation of the FER/MOR composite molecular
sieve obtained. In certain embodiments, after the reactor vessel is cooled with running
water, solid-liquid separation is achieved by centrifuging, thus separating the solid
material from the mother liquor within the resultant mixture, the pH of the resultant
solid then reaching 8-9 after washing in water, after which it is dried yielding the
composite molecular sieve sample.
[0072] In certain embodiments of this application, an organic template contained within
the FER seed crystals or MOR seed crystals is eliminated by calcining before the mixing
stage.
[0073] FER seed crystal or MOR seed crystal molecular sieve can be subjected to exchange
using current ionic exchange technology, this resulting in the replacement of inorganic
cations such as sodium ions within the FER seed crystals or MOR seed crystals with
other cations, for instance ammonium ions, hydrogen ions, magnesium ions, zinc ions
or gallium ions, resulting in an ammonium type, hydrogen type, magnesium type, zinc
type or gallium type molecular sieve. In certain embodiments, The FER seed crystals
or MOR seed crystals are ammonium type molecular sieve, hydrogen type molecular sieve
or sodium type molecular sieve.
[0074] According to the method of this application, by adjusting the proportion of FER and
MOR seed crystals, it is possible to obtain an FER/MOR composite molecular sieve the
crystal phase proportions of which can be adjusted. In the FER/MOR composite molecular
sieve synthesised according to the method of this application, the mass percentage
of the FER/MOR composite molecular sieve accounted for by the FER crystal phase is
0-100%. According to certain embodiments of this application, during synthesis of
the FER/MOR composite molecular sieve, the mass percentage of FER/MOR composite molecular
sieve accounted for by the FER crystal phase is at least 8%. According to certain
embodiments of this application, during synthesis of the FER/MOR composite molecular
sieve, the mass percentage of FER/MOR composite molecular sieve accounted for by the
FER crystal phase is at least 13%, or 20%, or 40%, or 45%, or 65%, or 75% or 83%.
[0075] By mechanically mixing single-phase FER crystalline molecular sieve with single-phase
MOR crystalline molecular sieve it is possible to obtain a mechanical mixture. When
compared with a mechanical mixture, the FER/MOR composite molecular sieve prepared
according to this application is significantly different in terms of both structure
and diffusion performance. As can be seen in the UV-Raman spectrum in figure la, it
is possible to observe five-membered ring and four-membered ring vibration at the
374cm
-1 peak and 433cm
-1 peak of the MOR molecular sieve sample; the FER molecular sieve exhibits a five-membered
ring vibration peak at around 406cm
-1. In the UV-Raman spectrum corresponding to the mechanical mixture, the three peaks
are superimposed, the peaks not having changed. Where the FER/MOR composite molecular
sieve according to this application is concerned, the 406 and 433cm
-1 peaks have coalesced, possibly indicating that the formation of a coexisting phase
within the FER/MOR composite molecular sieve has led to changes in the T-O-T bond
angle or the creation of new T-O-T bonds, whereby the T-O-T bonds referred to are
the Si-0-Si bond or the Si-O-Al bond. In the low-temperature hyperpolarized
129Xe NMR spectrum (figure 1b) it can be seen that the exchange rate of Xenon (Xe) adsorbed
within the 10-membered rings and 12-membered rings of the composite molecular sieve
is significantly higher than that corresponding to the mechanical mixture, demonstrating
that the composite molecular sieve possesses better channel interconnectivity. The
above characterization results directly confirm that it is FER/MOR composite molecular
sieve and not a simple mechanical mixture that has been prepared according to this
application.
[0076] Disclosed herein but not forming part of the present invention is a sodium type FER/MOR
molecular sieve, it being possible to modify that sodium type FER/MOR molecular sieve
further using traditional ionic exchange technology allowing its use in different
catalytic reactions. By supplementing this modified FER/MOR molecular sieve with a
suitable substrate it is possible to use it in the manufacture of the catalysts required
by various chemical reactions, thus allowing its use in catalytic reactions. In the
skeletal isomerization of butene, the butene transformation rate, the isobutene specificity
and the isobutene yield are all closely connected with the proportion of the two phases
in the FER/MOR composite molecular sieve, whereby the optimal range of FER crystal
phase mass proportion in terms of FER/MOR composite molecular sieve mass is 40-60%.
[0077] In this application, an X Pert Pro X-ray diffractometer manufactured by the Dutch
company Panalytical was used, diffraction data in the 2θ = 5-40° range being measured,
yielding the mass percentage proportion of the FER crystal phase or MOR crystal phase
within the FER/MOR composite molecular sieve. Here the CuK α radiation is that of
a radiant tube, the tube voltage being 40 kV, the tube current being 50 mA, using
CaF
2 (analytically pure) as the internal standard (reference may be made to: Zhang Ling
et al. Small crystal ZSM-5/ZSM-11 composite molecular sieve synthesis. Petrochemical
Technology. 2008, No. 37 Supplement: 556-558).
Examples
[0078] The following non-restrictive examples provide a more detailed description of this
invention. It should be explained that, the presentation of the following examples
is purely for the purpose of providing further description of the technical characteristics
of this invention, and may not be interpreted as being for the purpose of restricting
this invention. The following examples do not contain any detailed descriptions of
traditional techniques (chemical synthesis technology etc.) the knowledge of which
would be common to general technicians in this field.
Example 1: Preparation of FER/MOR composite molecular sieve
(1) Raw materials:
[0079]
Silicon source: 5.24g of silicon dioxide (99.5 wt% SiO2, 0.5 wt% H2O);
Aluminium source: 2.64g of sodium metaaluminate solution (NaAlO2: 16.8 wt% Al2O3, 31.2 wt% NaOH, 52 wt% H2O);
Alkali: 0.8ml sodium hydroxide solution (0.1g NaOH/ml);
Water: 45.5g deionised water;
FER seed crystals: 0.283g ZSM-35 molecular sieve;
MOR seed crystals: 0.113g natural Mordenite zeolite.
SiO2 mass = 5.24 × 0.995 = 5.214g; atomic silicon mol number = 5.214 / 60 = 0.087mol;
atomic silicon converted mass (the mass of SiO2 calculated from the atomic silicon mol number) = 5.214g; Al2O3 mass = 2.64 × 0.168 = 0.444g; atomic aluminium mol number = 0.444 / 102 × 2 = 0.008
mol; atomic aluminium converted mass (the mass of Al2O3 calculated from the atomic aluminium mol number) = 0.444g; OH- mol number = (0.1 × 0.8 + 2.64 × 0.312) / 40 = 0.0226 mol; H2O mol number = (5.24 × 0.005 + 2.64 × 0.52 + 0.8 -0.08 +45.5) / 18 = 2.65 mol.
[0080] The proportion of the total mass of FER seed crystals and MOR seed crystals accounted
for by the FER seed crystals in the initial reaction = 0.283 / (0.283 + 0.113) × 100%
= 71%. The pH of the reaction mixture was 11. The molar ratio of OH
- to Al within the reaction mixture was OH
-/Al = 0.0226 / 0.008 = 2.8:1, the molar ratio of Si to Al was Si/Al = 0.087 / 0.008
= 11:1, the molar ratio of water to Al being H
20/Al = 2.65 10.008 =331 :1, The mass of FER seed crystals and MOR seed crystals being
5% and 2% of the summation of the atomic silicon converted mass and atomic aluminium
converted mass (5.658g) respectively.
(2) Procedural steps
[0081] At the same time as mixing took place, 35.5g of deionised water and the silicon source
and sodium hydroxide solution were placed in that sequence within the reactor vessel,
then mixing continued until they were evenly mixed; the FER seed crystals and MOR
seed crystals were added to 10g of deionised water and ultrasound dispersion carried
out after which they were added to the above mentioned mixture, then further mixing
carried out until these were evenly mixed. The reaction mixture obtained was sealed
in a reaction vessel with a rotating oven, then left to undergo pre-crystallization
at 373.15 K (l00°C) for 10 hours, then the temperature was raised to 443.15 K (l70°C)
and it was left for a further 50 hours to undergo crystallization. During the pre-crystallization
and crystallization processes, the rate of rotation of the rotating oven was 40 rpm.
The reactor vessel was then cooled with running water. The solid material and mother
liquor were separated by centrifuging, then the solid material was washed with water
until the pH was 8-9, then it was air dried at 373.15 K (l00°C) for 8 hours, yielding
the crystalline product. When subjected to X-ray diffraction (XRD) analysis, the result
was as shown in figure 2, the product having the FER/MOR composite structure, the
percentage mass ratio of FER crystal phase to FER/MOR composite molecular sieve being
75%, the percentage mass ratio of MOR crystal phase to FER/MOR composite molecular
sieve being 25%; based on the SEM analysis, as can be seen in figure 3, the resultant
FER/MOR composite molecular sieve exhibits the characteristics of having two coexisting
phases.
Example 2: Preparation of FER/MOR composite molecular sieve
(1) Raw materials:
[0082]
Silicon source: 8.89 g of silicon dioxide (95 wt% SiO2, 5 wt% H2O);
Aluminium source: 3.9lg of sodium metaaluminate solution (NaAlO2: 16.8 wt% Al203,
31.2 wt% NaOH,
52 wt% H2O);
Alkali: 2.23ml sodium hydroxide solution (0.lg NaOH/ml);
Water: 135.0g deionised water;
FER seed crystals: 0.1g ZSM-35 molecular sieve;
MOR seed crystals: 0.1g natural Mordenite zeolite.
SiO2 mass = 8.89 × 0.995 = 8.446g; atomic silicon mol number = 8.446 / 60 = 0.141mol;
atomic silicon converted mass (the mass of SiO2 calculated from the atomic silicon mol number) = 8.446g; Al2O3 mass = 3.91 × 0.168 = 0.657g; atomic aluminium mol number = 0.657 / 102 × 2 = 0.012
mol; atomic aluminium converted mass (the mass of Al2O3 calculated from the atomic aluminium mol number) = 0.657g; OH mol number = (0.1 ×
2.23 + 3.91 × 0.312) / 40 = 0.0361 mol; H2O mol number = (8.89 × 0.05 + 3.91 × 0.52 + 2.23 -0.223 + 135) / 18 = 7.75 mol.
[0083] The proportion of the total mass of FER seed crystals and MOR seed crystals accounted
for by the FER seed crystals in the initial reaction = 0.1 / (0. L + 0.1) × 100% =
50%. The Ph of the reaction mixture was 10. The molar ratio of OH to Al within the
reaction mixture was OH/Al = 0.0361 / 0.012 = 3.0:1, the molar ratio of Si to Al was
Si/Al = 0.141 I 0.012 = 11.5:1, the molar ratio of water to Al being H
2O/Al = 7.75 / 0.012 =646:1, The mass of FER seed crystals and MOR seed crystals being
1% and 1% of the summation of the atomic silicon converted mass and atomic aluminium
converted mass (9.103g) respectively.
(2) Procedural steps
[0084] At the same time as mixing took place, 105.0g of deionised water and the silicon
source and sodium hydroxide solution were placed in that sequence within the reactor
vessel, then mixing continued until they were evenly mixed; FER seed crystals and
MOR seed crystals were added to 30g of deionised water and ultrasound dispersion carried
out after which they were added to the above mentioned mixture, then further mixing
carried Out until these were evenly mixed. The reaction mixture obtained was sealed
in a reaction vessel with a rotating oven, then left to undergo pre-crystallization
at 393.15 K (120°C) for 5 hours, then the temperature was raised to 435.15 K (162°C)
and it was left for a further 52 hours to undergo crystallization. During the pre-crystallization
and crystallization processes, the rate of rotation of the rotating oven was 30 rpm.
The reactor vessel was then cooled with running water. The solid material and mother
liquor were separated by centrifuging, then the solid material was washed with water
until the pH was 8-9, then it was air dried at 373.15 K (l00°C) for 8 hours, yielding
the crystalline product. When subjected XRD analysis the resultant product was found
to have the FER/MOR composite structure, the percentage mass ratio of FER crystal
phase to FER/MOR composite molecular sieve being 40%, the percentage mass ratio of
MOR crystal phase to FER/MOR composite molecular sieve being 60%.
Example 3: Preparation of FER/MOR composite molecular sieve
(1) Raw materials:
[0085]
Silicon source: 5.0 g of solid silica gel (92 wt% SiO2, 8 wt% H2O);
Aluminium source: 1.2g of sodium metaaluminate solution (NaAlO2: 16.8 wt% Al2O3,
31.2 wt% NaOH,
52 wt% H2O);
Alkali: 3.4ml sodium hydroxide solution (0.1g NaOH/ml);
Water: 65.2g deionised water;
FER seed crystals: 0.46g ZSM-35 molecular sieve;
MOR seed crystals: 0.46g natural Mordenite zeolite.
SiO2 mass = 5.0 × 0.92 = 4.6g; atomic silicon mol number = 4.6 / 60 = 0.077mol; atomic
silicon converted mass (the mass of SiO2 calculated from the atomic silicon mol number) = 4.6g; Al2O3 mass = 1.2 × 0.168 = 0.202g; atomic aluminium mol number = 0.202 / 102 × 2 = 0.004
mol; atomic aluminium converted mass (the mass of Al2O3 calculated from the atomic aluminium mol number) = 0.202g; OH- mol number = (0.1 × 3.4 + 1.2 × 0.312) / 40 = 0.0179 mol; H2O mol number = (5.0 × 0.08 + 1.2 × 0.52 + 3.4 -0.34 + 65.2) / 18 = 3.85 mol.
[0086] The proportion of the total mass of FER seed crystals and MOR seed crystals accounted
for by the FER seed crystals in the initial reaction = 0.46 / (0.46 + 0.46) × 100%
= 50%. The pH of the reaction mixture was 10. The molar ratio of OH
- to Al within the reaction mixture was OH
-/Al = 0.0179 / 0.004 = 4.5:1, the molar ratio of Si to Al was Si/Al = 0.077 / 0.004
= 19.5:1, the molar ratio of water to Al being H
2O/Al = 3.85 / 0.004 =963:1, The mass of FER seed crystals and MOR seed crystals being
10% and 10% of the summation of the atomic silicon converted mass and atomic aluminium
converted mass (4.802g) respectively.
(2) Procedural steps
[0087] At the same time as mixing took place, 35.2g of deionised water and the silicon source
and sodium hydroxide solution were placed in that sequence within the reactor vessel,
then mixing continued until they were evenly mixed; FER seed crystals and MOR seed
crystals were added to 30g of deionised water and ultrasound dispersion carried out
after which they were added to the above mentioned mixture, then further mixing carried
out until these were evenly mixed. The reaction mixture obtained was sealed in a reaction
vessel with a rotating oven, then left to undergo pre-crystallization at 353.15 K
(80°C) for 12 hours, then the temperature was raised to 443.15 K (l 70°C) and it was
left for a further 36 hours to undergo crystallization. During the pre-crystallization
and crystallization processes, the rate of rotation of the rotating oven was 60 rpm.
The reactor vessel was then cooled with running water. The solid material and mother
liquor were separated by centrifuging, then the solid material was washed with water
until the pH was 8-9, then it was air dried at 373.15 K (l00°C) for 8 hours, yielding
the crystalline product. When subjected to XRD analysis the resultant product was
found to the FER/MOR composite structure, the percentage mass ratio of FER crystal
phase to FER/MOR composite molecular sieve being 20%, the percentage mass ratio of
MOR crystal phase to FER/MOR composite molecular sieve being 80%.
Example 4: Preparation of FER/MOR composite molecular sieve
(1) Raw materials:
[0088]
Silicon source: 52.28g of colloidal silica (25.7 wt% SiO2, 0.3 wt% Na2O, 0.1 wt% Al2O3 and 73.9 wt% H2O);
Aluminium source: l.82g of aluminium hydroxide (66.50 wt% Al2O3, 33.5 wt% H2O); Alkali: 15.72 ml sodium hydroxide solution (0.1g NaOH/ml);
Water: 80.2g deionised water;
FER seed crystals: 0.29g ZSM-35 molecular sieve,
MOR seed crystals: 0.1g natural Mordenite zeolite.
SiO2 mass = 52.28 × 0.257 = 13.436g; atomic silicon mol number = 13.436 / 60 = 0.224mol;
atomic silicon converted mass (the mass of SiO2 calculated from the atomic silicon mol number) = 13.436g; Al2O3 mass = 1.82 × 0.665 + 52.28 × 0.001 = l.262g; atomic aluminium mol number = 1.262
/ 102 × 2 = 0.024 mol; atomic aluminium converted mass (the mass of Al2O3 calculated from the atomic aluminium mol number) = l.262g; OH mol number = (0.1 ×
15.72) 140 + (52.28 × 0.003) × 2 162 = 0.039 + 0.005 = 0.044 mol; H20 mol number = (52.28 × 0.739 + 1.82x 0.335 + 15.72- 1.572 + 80.2) / 18 = 7.42 mol.
[0089] The proportion of the total mass of FER seed crystals and MOR seed crystals accounted
for by the FER seed crystals in the initial reaction = 0.29 / (0.29 + 0.1) × 100%
= 75%. The pH of the reaction mixture was 11. The molar ratio of OH
- to Al within the reaction mixture was OH/Al = 0.044 / 0.024 = 1.8:1, the molar ratio
of Si to Al was Si/Al = 0.224 / 0.024 = 9:1, the molar ratio of water to Al being
H
2O/Al = 7.42 / 0.024 =309:1, The mass of FER seed crystals and MOR seed crystals being
2% and 0.7% of the summation of the atomic silicon converted mass and atomic aluminium
converted mass (14.698g) respectively.
(2) Procedural steps
[0090] t the same time as mixing took place, 50.2g of deionised water and the silicon source
and sodium hydroxide solution were placed in that sequence within the reactor vessel,
then mixing continued until they were evenly mixed; FER seed crystals and MOR seed
crystals were added to 30g of deionised water and ultrasound dispersion carried out
after which they were added to the above mentioned mixture, then further mixing carried
out until these were evenly mixed. The reaction mixture obtained was sealed in a reaction
vessel with a rotating oven, then left to undergo pre-crystallization at 393.15 K
(120°C) for 10 hours, then the temperature was raised to 443 . 15 K (l70°C) and it
was left for a further 38 hours to undergo crystallization. During the pre-crystallization
and crystallization processes, the rate of rotation of the rotating oven was 60 rpm.
The reactor vessel was then cooled with running water. The solid material and mother
liquor were separated by centrifuging, then the solid material was washed with water
until the pH was 8-9, then it was air dried at l00°C for 8 hours, yielding the crystalline
product. When subjected to XRD analysis the resultant product was found to have the
FER/MOR composite structure, the percentage mass ratio of FER crystal phase to FER/MOR
composite molecular sieve being 83%, the percentage mass ratio of MOR crystal phase
to FER/MOR composite molecular sieve being 17%.
Example 5: Preparation of FER/MOR composite molecular sieve
(1) Raw materials:
[0091]
Silicon source: 7.31 g of solid silica gel (92 wt% SiO2, 8 wt% H2O);
Aluminium source: 0.67g of SB powder (77.5 wt% Al2O3, 22.5 wt H2O);
Alkali: 17.11ml potassium hydroxide solution (0.1g KOH/ml); 9.4lg of ammonium hydroxide
(25.0 wt%, pH=l0);
Water: 117.lg deionised water;
FER seed crystals: 0.18g ZSM-35 molecular sieve,
MOR seed crystals: 0.36g natural Mordenite zeolite.
SiO2 mass = 7.31 × 0.92 = 6.72g; atomic silicon mol number = 6.725 / 60 = 0.112mol; atomic
silicon converted mass (the mass of Si02 calculated from the atomic silicon mol number) = 6.725g; Al2O3 mass = 0.67 × 0.7751 = 0.519g; atomic aluminium mol number = 0.519/102 × 2 = 0.01
mol; atomic aluminium converted mass (the mass of Al2O3 calculated from the atomic aluminium mol number) = 0.519g; the OH mol number is the
mol number of free OH- within the solution. The OH mol number includes the mol number
of free OH. stemming from the potassium solution and the mol number of free OH stemming
from the ammonium hydroxide. Based on the ammonium hydroxide having a pH of 10, the
concentration of the ammonium hydroxide free H+ was 10-10 mol/L, the concentration of OH being 10-4 mol/L, hence being 10-7 mol/mL. The OH mol number = 0.1 × 17.11 / 56 + 10·7 × 9.41= 0.0306 mol; H20 mol number = (7.31 × 0.08 + 0.67 × 0.225 + 17.11 -1.711 + 9.41 × 0.75 + 117.1)/
18 = 7.8 mol.
[0092] The proportion of the total mass of FER seed crystals and MOR seed crystals accounted
for by the FER seed crystals in the initial reaction = 0.18 / (0.18 + 0.36) × 100%
= 33%. The pH of the reaction mixture was 10. The molar ratio of OH to Al within the
reaction mixture was OH/Al = 0.0306 10.01 = 3.1: 1, the molar ratio of Si to Al was
Si/Al = 0.112 / 0.0l = 11:1, the molar ratio of water to Al being H
20/Al = 7.8 10.01 = 780: 1, the mass of FER seed crystals and MOR seed crystals being
2.5% and 5.0% of the summation of the atomic silicon converted mass and atomic aluminium
converted mass (7.244g) respectively.
(2) Procedural steps
[0093] At the same time as mixing took place, 87.1g of deionised water and the silicon source
and potassium hydroxide solution were placed in that sequence within the reactor vessel,
then mixing continued until they were evenly mixed; FER seed crystals and MOR seed
crystals were added to 30g of deionised water and ultrasound dispersion carried out
after which they were added to the above mentioned mixture, then further mixing carried
out until these were evenly mixed. The reaction mixture obtained was sealed in a reaction
vessel with a rotating oven, then left to undergo pre-crystallization at 353.15 K
(80°C) for 10 hours, then the temperature was raised to 453.15 K (180°C) and it was
left for a further 48 hours to undergo crystallization. During the pre-crystallization
and crystallization processes, the rate of rotation of the rotating oven was 90 rpm.
The reactor vessel was then cooled with running water. The solid material and mother
liquor were separated by centrifuging, then the solid
material was washed with water until the pH was 8-9, then it was air dried at 373.15
K (l 00°C) for 8 hours, yielding the crystalline product. When subjected to XRD analysis
the resultant product was found to have the FER/MOR composite structure, the percentage
mass ratio of FER crystal phase to FER/MOR composite molecular sieve being 13%, the
percentage mass ratio of MOR crystal phase to FER/MOR composite molecular sieve being
87%.
Example 6: Preparation of FER/MOR composite molecular sieve
(1) Raw materials:
[0094]
Silicon source: 21.4 g of tetraethoxysilane (28.0 wt% SiO2, 72.0 wt% H2O);
Aluminium source: 2.0g of sodium metaaluminate solution (NaAlO2: 16.8 wt%, Al2O3,
31.2 wt% NaOH,
52 wt% H2O);
Alkali: 2.2ml sodium hydroxide solution (0.lg NaOH/ml);
Water: 70.9g deionised water;
FER seed crystals: 0.507g ZSM-35 molecular sieve;
MOR seed crystals: 0.253g natural Mordenite zeolite.
SiO2 mass = 21.4 × 0.28 = 5.992g; atomic silicon mol number = 5.992 / 60 = 0.100mol; atomic
silicon converted mass (the mass of SiO2 calculated from the atomic silicon mol number) = 5.992g; Al2O3 mass = 2.0 × 0.168 = 0.336g; atomic aluminium mol number = 0.336 / 102 × 2 = 0.006
mol; atomic aluminium converted mass (the mass of Al2O3 calculated from the atomic aluminium mol number) = 0.336g; OH mol number = (0.1 ×
2.2 + 2.0 × 0.312) / 40 = 0.021 mol; H2O mol number = (21.4 × 0.72 + 2.0 × 0.52 + 2.2 - 0.22 + 70.9) / 18 = 4.96 mol.
[0095] The proportion of the total mass of FER seed crystals and MOR seed crystals accounted
for by the FER seed crystals in the initial reaction = 0.507 / (0.507 + 0.253) × 100%
= 67%. The pH of the reaction mixture was 11. The molar ratio of OH to Al within the
reaction mixture was OH/Al = 0.021 I 0.006 = 3.5:1, the molar ratio of Si to Al was
Si/Al = 0.100 / 0.006 = 16.5:1, the molar ratio of water to Al being H
2O/Al = 4.96 / 0.006 = 827: 1, the mass of FER seed crystals and MOR seed crystals
being 8% and 4% of the summation of the atomic silicon converted mass and atomic aluminium
converted mass (6.328g) respectively.
(2) Procedural steps
[0096] At the same time as mixing took place, 60.9g of deionised water and the silicon source
and sodium hydroxide solution were placed in that sequence within the reactor vessel,
then mixing continued until they were evenly mixed; FER seed crystals and MOR seed
crystals were added to lOg of deionised water and ultrasound dispersion carried out
after which they were added to the above mentioned mixture, then further mixing carried
out until these were evenly mixed. The reaction mixture obtained was sealed in a reaction
vessel with a rotating oven, then left to undergo pre-crystallization at 363.15 K
(90°C) for 12 hours, then the temperature was raised to 43 8. 15 K (165°C) and it
was left for a further 64 hours to undergo crystallization. During the pre-crystallization
and crystallization processes, the rate of rotation of the rotating oven was 60 rpm.
The reactor vessel was then cooled with running water. The solid material and mother
liquor were separated by centrifuging, then the solid material was washed with water
until the pH was 8-9, then it was air dried at 373.15 K(l00°C) for 8 hours, yielding
the crystalline product. When subjected to XRD analysis the resultant product had
the FER/MOR composite structure, the percentage mass ratio of FER crystal phase to
FER/MOR composite molecular sieve being 65%, the percentage mass ratio of MOR crystal
phase to FER/MOR composite molecular sieve being 35%.
Example 7: Preparation of FER/MOR composite molecular sieve
(1) Raw materials:
[0097]
Silicon source: 4.8g of silicon dioxide (99.5 wt% SiO2);
Aluminium source: 2.4g of sodium metaaluminate solution (NaAlO2: 16.8wt% Al2O3 31.2 wt% NaOH, 52 wt% H2O);
Alkali: 2.07ml sodium hydroxide solution (0.1g NaOH/ml);
Water: 52.7g deionised water;
FER seed crystals: 0.1562g ZSM-35 molecular sieve;
MOR seed crystals 0.0521g natural Mordenite zeolite.
Si02 mass = 4.8 × 0.995 = 4.776g; atomic silicon mol number = 4.776 / 60 = 0.0796mol;
atomic silicon converted mass (the mass of Si02 calculated from the atomic silicon mol number) = 4.776g; Ah03 mass = 2.4 × 0.168 = 0.403g; atomic aluminium mol number = 0.403 / 102 × 2 = 0.008
mol; atomic aluminium converted mass (the mass of Al2O3, calculated from the atomic aluminium mol number) = 0.403g; OH mol number = (0.1
× 2.07 + 2.4 × 0.312) 140 = 0.0239 mol; H2O mol number = (4.8 × 0.005 + 2.4 × 0.52 + 2.07 -0.207 +52.7) / 18 = 3.10 mol.
[0098] The proportion of the total mass of FER seed crystals and MOR seed crystals accounted
for by the FER seed crystals in the initial reaction = 0.1562 / (0.1562 + 0.0521)
× 100% = 75%. The pH of the reaction mixture was 11. The molar ratio of OH to Al within
the reaction mixture was OH-/Al = 0.0239 / 0.008 = 3.0:1, the molar ratio of Si to
Al was Si/Al = 0.0796 / 0.008 = 10:1, the molar ratio of water to Al being H
2O/Al = 3.10 / 0.008 = 387:1, The mass of FER seed crystals and MOR seed crystals being
3% and 1% of the summation of the atomic silicon converted mass and atomic aluminium
converted mass (5. I 79g) respectively.
(2) Procedural steps
[0099] At the same time as mixing took place, 42.7g of deionised water and the silicon source
and sodium hydroxide solution were placed in that sequence within the reactor vessel,
then mixing continued until they were evenly mixed; FER seed crystals and MOR seed
crystals were added to l0
g of deionised water and ultrasound dispersion carried out after which they were added
to the above mentioned mixture, then further mixing carried out until these were evenly
mixed. The reaction mixture obtained was sealed in a reaction vessel with a rotating
oven, then left to undergo pre-crystallization at 353.15 K (80°C) for 10 hours, then
the temperature was raised to 433.15 K(160°C) and it was left for a further 64 hours
to undergo crystallization. During the pre-crystallization and crystallization processes,
the rate of rotation of the rotating oven was 40 rpm. The reactor vessel was then
cooled with running water. The solid material and mother liquor were separated by
centrifuging, then the solid material was washed with water until the pH was 8-9,
then it was air dried at 373.15 K (l 00°C) for 8 hours, yielding the crystalline product.
When subjected to XRD analysis, the resultant product was found to have the FER/MOR
composite structure, the percentage mass ratio of FER crystal phase to FER/MOR composite
molecular sieve being 45%, the percentage mass ratio of MOR crystal phase to FER/MOR
composite molecular sieve being 55%.
[0100] When compared to example 4, the proportion of FER crystal phase to FER/MOR composite
molecular sieve in example 7 was found to be the same as example 4, however in example
7 there was an increase in the mol ratio between OH and Al within the reaction mixture,
which increased the proportion of the MOR crystal phase within the FER/MOR composite
molecular sieve. As a result of this, when the proportion of the mass of FER seed
crystals in terms of the total mass of FER seed crystals and MOR seed crystals remains
constant, the mol ratio of OH to Al within the reaction mixture increases and the
proportion of the MOR crystal phase within the FER/MOR composite molecular sieve increases;
when the mol ratio of OH
- to Al within the reaction mixture drops, the proportion of the MOR crystal phase
within the FER/MOR composite molecular sieve drops.
Example 8: Measurement of the catalytic performance of catalyst within the 1-butene
skeletal isomerization reaction
[0101] The FER/MOR composite molecular sieve products resulting from examples 1,2 and 3
were placed in a 0.5 Mol/L ammonium nitrate solution and mixed for 2 hours, then ammonium
ions were used to exchange the sodium ions within the molecular sieve, the solid material
then being separated from the liquid by filtration, then the solid material was washed
for I hour in deionised water, then the above mentioned exchange, filtration, washing,
exchange and filtration steps were repeated, yielding the ammonium type molecular
sieve. The ammonium type molecular sieve obtained was then calcined at 823.15 K (550°C)
for 4 hours, then processed in an aqueous steam atmosphere at 823.15 K (550°C) for
3 hours, yielding the catalysts A, B and C.
[0102] Catalyst comparison: hydrogen type single-phase FER crystalline molecular sieve and
single-phase MOR crystalline molecular sieve were mixed mechanically, yielding the
catalyst D, within which the mass percentage ratio of FER molecular sieve was 40%,
the mass percentage ratio of MOR molecular sieve being 60%.
Catalyst A, B, C and D reaction properties measurement testing:
[0103] Catalyst reaction property testing took place within a standard fixed bed reactor,
the reactor tube having a diameter of l0mm, a length of 32cm and a catalyst load of
lg. The catalyst was subjected to pre-processing at 773.15 K (500°C) in an N
2 atmosphere for I hour, then being cooled to room temperature within the N
2 atmosphere. Reaction conditions: temperature 673.15 K (400°C), pressure 0.1 MPa;
I-butene weight space velocity 8 h
-1 reaction raw material composition was: I-butene 51.3%, N
2 48.7% (volumetric proportion). The raw materials passed through the catalyst bed
from the top downwards, reaction product being sampled at different reaction time
points, online analysis of the composition of the resultant products being carried
out using an Ah0
3-plot chromatography column (manufactured by Agilent) and a Varian-3800 gas chromatograph
(manufactured by the US company Varian) (reference:
Shang Yongchen et al. The MCM-49 molecular sieve catalyst I-butene skeletal isomerization
reaction. Chinese Journal of Catalytics. 2004, 25 (2): 158- 162). The method for calculating the yield Y of isobutene being as follows:

[0104] The quantities of isobutene and I-butene referred to are all molar quantities.
[0105] The isobutene yield in the 1-butene skeletal isomerization reaction using catalysts
A, B, C and D is shown in table 1.
Table 1 : Isobutene yield in the I-butene skeletal isomerization reaction using catalysts
A, B, C and D
Catalyst (FER/MOR mass ratio) |
Isobutene yield % |
2 h |
10 h |
20 h |
40 h |
50 h |
A (75: 25) |
23 |
24 |
25 |
26 |
26 |
B (40:60) |
21 |
26 |
28 |
32 |
36 |
C (20:80) |
15 |
13 |
IO |
9 |
7 |
D (40:60) |
14 |
20 |
22 |
25 |
30 |
[0106] From the reaction results shown in table 1, it can be deduced that isobutene yield
from the I-butene skeletal isomerization reaction is closely connected with the proportion
of the two phases within the FER/MOR composite molecular sieve. Of the catalysts investigated,
the sample from example 2, the FER mass percentage proportion of which was 40%, exhibited
the best butene skeletal isomerization performance, with the highest resultant isobutene
yield, whilst exhibiting excellent reaction stability. Although the FER crystal phase
mass percentage proportion of the mechanically mixed single-phase FER crystalline
molecular sieve and single-phase MOR crystalline molecular sieve was also 40%, the
I-butene skeletal isomerization performance of FER/MOR composite molecular sieve B
was superior to that of the molecular sieve D consisting of mechanically mixed single-phase
FER crystalline molecular sieve and single-phase MOR crystalline molecular sieve.
In the I-butene skeletal isomerization reaction, isobutene yield was closely connected
with the proportion of the two phases within the FER/MOR composite molecular sieve,
whilst the optimum range of the mass percentage proportion of the FER crystal phase
within the FER/MOR composite molecular sieve was 40-60% (data not displayed).
[0107] Unless otherwise stated in the text, where the singular form "I", "a/an" and "the
aforementioned" is used, this may also refer to a plural number. Furthermore, where
this text uses the expression "containing" and/or "including" this refers to the appended
characteristics, figures, steps, operations, components and/or parts, but does not
exclude the existence or addition of one or more other characteristics, figures, steps,
operations, components, parts and/or other combinations.
[0108] The sizes and values revealed in this text should not be considered as being restricted
to the actual values recorded. In actual fact, unless otherwise stated, any such size
recorded not only refers to the value recorded but also near values within a functionally
equivalent range. For instance, where the size given is "40mm" this may be taken to
mean "about 40mm". Furthermore, where the interpretation or definition of a term within
this text contradicts the interpretation or definition of a similar term within a
quoted document, the interpretation or definition of that term according to this text
shall prevail.